Bond Strength of Self-adhesive Cement to Bis-acrylic Composite and Acrylate-polymer

Introduction: Bis-acrylic composite resin and CAD/CAM acrylate polymer materials possess good long-term stability and can be used for long-term provisional restorations when cemented with resin cements.

Objective: The objective of this study was to compare the shear bond strength of self-adhesive resin cement (RelyX Unicem Clicker, 3MESPE) to bis-acrylic composite resin and CAD/CAM acrylate polymer.

Method: Ten slabs, measuring 15mm x 10mm x 1.5mm, were made of 4 bis-acrylic composite  resin materials, (1)Protemp 4 (3MESPE), (2)Luxatemp Fluorescence (DMG), (3)Telio CS C&B (Ivoclar) and (4)Integrity (Dentsply); and 1 CAD/CAM acrylate polymer, (5)CAD-Temp (Vita). Slabs were cut from blocks with a saw (Isomet; Buehler). Resin cement plugs measuring 2.3mm in diameter and 5mm in height were made with a jig (Ultradent). The cement was hand mixed, injected into the jig with a disposable syringe (Centrix) and polymerized for 20 seconds with an LED polymerization unit (Bluephase, Ivoclar). Specimens were stored in deionized water (37ºC, 1 hour). After storage, shear bond test was performed in a universal testing machine (5566A, Instron) with a 1-kN cell, a 0.5mm/min cross-head speed and a half-moon shear apparatus. Results were analyzed by ANOVA followed by Tukey HSD test (α=0.05).

Result: Means and standard deviations of shear bond strength values (MPa) were: (1)36.41±15.5; (2)18.35±3.90; (3)34.21±5.27; (4)37.70±9.96 and (5)6.19±2.63. Shear bond strength values for Integrity, Protemp 4 and Telio CS C&B were statistically significantly greater when compared with all other materials. Whereas shear bond strength values for Vita CAD-Temp were statistically significantly lower than all other materials.

Conclusion: Within the limitations of this study, it was concluded that the bond strength of RelyX Unicem Clicker is greater with bis-acrylic materials than with CAD/CAM acrylate polymer.